Tamarillo plant named &#39;Sweeten&#39;

ABSTRACT

A new and distinct tamarillo variety is described. The variety results from selection among a population of seedlings derived from hybridization among red, amber, and yellow-fruited tamarillo selections. This new variety is characterized by bright red skin color and sweet flavor. The new variety appears suitable for the fresh fruit market and has been named ‘Sweeten’.

GENUS AND SPECIES OF PLANT CLAIMED

Cyphomandra betacea

VARIETY DENOMINATION

‘Sweeten’

BACKGROUND OF THE INVENTION

The invention relates to a tamarillo (Cyphomandra betacea) tree bearingfruit suitable for the fresh fruit market.

The tree tomato, renamed the tamarillo in New Zealand around 1970, undercultivation produces an edible fruit, similar in size and shape to a henegg. Generally believed to be native to the Andean region of Peru, andextending in range into Chile, Ecuador, and Bolivia, it is cultivated inArgentina, Brazil, Colombia, and Venezuela.

Grown in New Zealand both as a commercial crop and by amateur growers,seed is thought to have been first introduced in the late 1800's,obtained from a missionary in Ecuador. In the wild, the fruit isgenerally small, splotchy and yellow or pale red in color. Selection andimprovement by nurserymen have resulted in large red-fruited strains.Golden cultivars, ranging yellow to amber in external coloration, havealso been introduced.

The tamarillo is a member of the Solanaceae family. It is a subtropicalrather than tropical plant, and while succeeding in cooler climates,does best where the temperature remains above 10° C. Tamarillos arerapidly growing trees which produce good crops after 18 months. They arefrost tender, seedlings and cuttings being most vulnerable in theirfirst year, more mature plants tending to recover after frost damage solong as it is not too severe or prolonged.

Fruit are highly attractive and are usually cut and eaten with a spoon.Some people find the skin astringent and flesh too acid to their taste.However, the flavor overall is sweet to sub-acid, and the pulp juicy.Tamarillos are considered a nutritious fruit containing good quantitiesof several important vitamins including A, B6, C and E, are rich in ironand potassium, low in sodium, and a good source of fibre. While anexcellent fruit for fresh consumption it has a limited storage life,suffering from chilling injury and post-harvest pathogens if maintainedbelow 5° C. for any sustained period of time. Fruit processes extremelywell, especially as pulp, puree, and juice.

SUMMARY OF THE INVENTION

The new variety was selected from a population of seedlings derived fromconventional hybridization among unpatented red, amber, andyellow-fruited tamarillo germplasm available in New Zealand. Theobjective of the crossing program was to produce a variety with sweeterfruit than was typically available, and suitable for commercial fruitproduction. The new variety was selected in the 1993-94 fruiting seasonfrom among seedlings located on land controlled by the Horticulture andFood Research Institute of New Zealand Limited at Northland, NewZealand, and was assigned the breeder code, 4G3. The new variety hassince been named ‘Sweeten’. The parents of the new variety are notknown. The new variety differed from the possible parent varieties byhaving a combination of bright red fruit skin colour and sweet flavor.

The original selection was asexually propagated as hardwood cuttingsover the next twelve years. Throughout this time the plants wereobserved to be true to the original parent plant. The characteristics ofthe new variety are stable and transmitted without change throughsucceeding generations.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs show typical specimens of the plant,foliage and fruit of the new variety as depicted in colors as nearlytrue as is reasonably possible to make the same in a color illustrationof this character.

FIG. 1 shows a young tree of the variety ‘Sweeten’ in an orchard.

FIG. 2 shows an example of the main trunk of the plant of the variety‘Sweeten’.

FIG. 3 shows an example of a mature, and slightly woody, section themain trunk of the plant of the variety ‘Sweeten’.

FIG. 4 shows an example of a mature leaf of the plant of the variety‘Sweeten’; view is of the upper surface of the leaf.

FIG. 5 shows examples of an immature leaf of the plant of the variety‘Sweeten’; view is of the upper surface of the leaves.

FIG. 6 shows an example of a mature leaf of the plant of the variety‘Sweeten’; view is of the lower surface of the leaf.

FIG. 7 shows examples of an immature leaf of the plant of the variety‘Sweeten’; view is of the lower surface of the leaves.

FIG. 8 shows examples of emerging immature leaves of the plant of thevariety ‘Sweeten’.

FIG. 9 shows the inflorescence of the plant of the variety ‘Sweeten’.

FIG. 10 shows buds and flowers of the plant of the variety ‘Sweeten’.

FIG. 11 shows fruit of the plant of the variety ‘Sweeten’ on the tree.

FIG. 12 shows fruit of the plant of the variety ‘Sweeten’ in the studio.

FIG. 13 shows fruit of the plant of the variety ‘Sweeten’; view is ofthe cut surface in longitudinal and equatorial section.

FIG. 14 shows fruit of the plant of the variety ‘Sweeten’; view is ofthe whole fruit and the cut surface equatorial section.

DETAILED BOTANICAL DESCRIPTION

Horticultural terminology is used in accordance with UPOV guidelines.All dimensions in millimeters, weights in grams (unless otherwisestated). Where a color reference is given these refer to the R.H.S.Colour Chart, The Royal Horticultural Society, London. 4^(th) Edition,2001. The specimens described were grown at HortResearch Kerikeri,Northland, New Zealand.

Published environmental data relating to growing conditions forNorthland, New Zealand is as follows (based on mean annual values1971-2000):

-   -   Rainfall 1671 mm    -   Sunshine hours 1964    -   Ground frost 12 days    -   Heat units 1912 degree days

-   Plant description:    -   -   Plant and foliage.—a small semi-woody, evergreen, tree with            a short stem with a crown of divergent branches. The plant            exhibits an overall upright growth habit with medium vigor            (FIG. 1). It is shallow-rooted, with a fine fibrous root            system. Mature plant height is commonly in the range 3000 mm            to 5500 mm, although this may vary with the growing            conditions. The main trunk of the plant is typically green            (near Green 143C) in color (FIG. 2). Many light colored            lenticels are evident (near Green 142D in color) (FIG. 2).            The most mature sections, typically near the base of the            trunk, tend to more brown in color (near Greyed-orange 175A            and 175C), and appear more woody (FIG. 3). The trunk is            smooth. The plant is multi-branched, the main branches            arising from the central stem typically at about 160 cm from            ground level. The branching pattern is highly influenced by            the terminal flowering habit; the occurrence of a terminal            inflorescence causing the buds of two subtending leaves to            break and form shoots. No pubescence is evident on the            trunk, branches, or other stems. Leaves are overall large,            ranging in dimension depending on the maturity of the            individual; mature, fully expanded, leaf width averages in            the range 225 mm to 322 mm, while length of the same leaves            averages 330 mm to 440 mm (FIG. 4). Immature leaves, while            appearing expanded are typically both shorter in length            (around 160 mm) and less broad (around 110 mm) (FIG. 5). The            leaves of the ‘Sweeten’ plant are arranged alternately. The            leaves (both mature and immature) are cordate in shape, the            bases of mature leaves are overlapping and the leaf tip is            acuminate (FIGS. 4 and 5). The coloration of the upper            surface of the leaf is green (near Green 137A), the under            side being markedly lighter in color (near Green 138B)            (FIGS. 4 and 6). Emerging leaves have strong anthocyanin            coloration (near Red-purple 59A) (FIG. 8). The leaf margin            is slightly undulate and on mature leaves some slight            anthocyanin coloration is evident (near Red 53A) around the            margin. A marked reticulate venation pattern is evident on            the upper surface of the leaf as course veins, near            Yellow-green 152B in color. The leaf surface is smooth            overall although leaves can appear slightly wavy. When            rubbed or brushed against the foliage gives off a            distinctive musky smell, not uncommon among members of the            Solanaceae family. The leaf stem of mature leaves ranges            about 80 mm to 210 mm in length, while stems of immature            leaves range about 40 mm to 110 mm in length. The diameter            of mature leaf stems is about 11 mm while the diameter of            immature leaf stems is about 6 mm. The leaf stems are            variable in color, often darker towards the base (near            Greyed-orange 177D) and lighter towards the base of the leaf            blade (near Grey-brown 199C) although are predominantly            green-flecked (near Greyed-green 194C). The flowers and            fruit are borne on the previous year's growth. Flower buds            typically arise about 10 mm to 15 mm from the base of 1 year            old shoots.        -   Inflorescence.—white flowers are borne on trusses (a            multi-flowered inflorescence) (FIG. 9). Trusses are            comprised of smooth, slender pedicels bearing multiple            flower buds and flowers. The hierarchy of flower opening            occurs from the bud nearest to the plant (most mature) to            the tip of the truss (least mature); a truss may comprise            flowers of different physiological maturity, from fully open            flowers through to immature flower buds, at any one time.            Flowering occurs over several weeks. A typical truss may            carry in excess of 15 flowers. Each flower is rotate in form            with five petals per flower (FIG. 10). The petal width is            typically about 5 mm and about 8.5 mm in length. The petal            tips are acuminate in shape, the tips curve back and under,            and the petals are fused at the base. The average maximum            width across the open flower is about 22.7 mm. The regular            calyx is near Yellow-green 145C in color, as is the petiole.            The petiole length of a mature flower averages about 16.24            mm and the diameter averages about 1.43 mm. An unopened bud            is typically near Red 56D in color, and averages a maximum            width of about 7.17 mm and 11.74 mm in length. The petiole            of an unopened bud averages about 13.15 mm in length, and            about 1.36 mm in diameter. Bright yellow pollen (near            Yellow-orange 16A in color) is clearly visible within the            open flowers. The flowers have no discernable fragrance. The            plant is self fertile and is typically pollinated by bees.            Un-pollinated flowers drop naturally.        -   Fruit.—fruit is typically borne singly, or in clusters of            3-12; fruit hang pendently in the tree (FIG. 11). The fruit            is shiny, smooth-skinned and egg-shaped. Fruit shape is            ovate in profile; on the basis of fruit length to width            ratio, fruit is longer than broad. The shape of the fruit            apex is rounded. The shape of fruit of ‘Sweeten’ differs            from those of the unpatented variety ‘Red Beau’; fruit of            this variety being elliptic with a more pointed apex.            Average fruit weight is approximately 66.5 g. On average            fruit are about 60 mm long and 45.2 mm in diameter (at the            widest point). Fruit size is related to seed content. Fruit            size is achieved in about 15-17 weeks from fruit set Fruit            color is orange-red; external color of immature fruit in the            range near Green 138A to 138B, internal color near Green            145D. Deep red color (near Red 53B) develops as fruit reach            harvest maturity (FIGS. 11 and 12). Faint darker, irregular            longitudinal stripes are sometimes evident in the skin at            full maturity (FIG. 11). The skin is tough, and is not            edible, having a slightly resinous flavor. The calyx            persists with the fruit. The fruit stem is near Yellow-green            144B in color when the fruit is ready to harvest. When cut            the bright colored flesh and pulp is revealed (ranging near            Orange 26B to 25A). When viewed in longitudinal section the            fruit can be seen to be in a typical arrangement with seeds            lodged within the pulpy endocarp surrounded in turn by the            firmer flesh of the mesocarp. The central placenta and two            longitudinal compartments containing the seeds and pulpy            endocarp are evident in both the longitudinal and equatorial            views of the cut fruit (FIG. 13). The flesh is sweet to            sub-acid in flavor, more tangy than sugary. The internal            flesh or pulp is firm but juicy, and contains many seeds            like a tomato (FIG. 14). The seeds are overall black in            color although the close association with the highly colored            pulp and juice (near Greyed-purple 185B) gives the            impression they are also somewhat colored. The seeds are            nearly flat, round, and hard. On average the seeds are about            3.8 mm in diameter (at the widest point) and about 1.0 mm            thick. The flesh, pulp, and seeds are edible. Soluble solids            concentration of the juice from fruit at eating maturity is            typically greater than 9° Brix. The cut surface of fruit            does not brown readily. The juice will cause an indelible            stain on cloth or other light surfaces. The seeds are near            Greyed-purple 186B in color when dry. Seed numbers vary per            fruit depending on growing conditions and the efficacy of            pollination; the observed sample averaged about 280 seeds            per fruit and total seed weighed on average about 2 g per            fruit (when fresh).        -   Harvest and yield.—trees typically commence to crop within            18 months from planting. At physiological maturity, and            under commercial production management, the annual yield per            tree is about 20-30 kg. Fruits ripen progressively, and are            harvested by selective hand picking of the most mature.            Typically fruit reaches physiological maturity about 21            weeks from pollination. While fruit are overall firm, a            slightly softening is detectible as fruit reach harvest            maturity, and further softening occurs prior to being eating            ready. The tough skin and firm flesh allow the fruit to be            easily handled for post-harvest sorting and packing; the            fruit also ships well, although storage life is short. Fruit            commences ripening in early autumn (late March, early April)            in Northland, New Zealand. Fruit continue to ripen and are            able to be harvested through the autumn and winter months            until spring (mid October). It is not uncommon for trees to            bear immature and mature fruit as well as flowers,            simultaneously.        -   Pest and disease resistance.—tamarillo trees are easily            infected with tamarillo mosaic virus, which results in            production of blotchy, streaked unattractive fruit, and,            leaf mottling. Resistance to insect pests is unknown. The            most common insect pest effecting tamarillo in New Zealand            is Whitefly (most likely Trialeurodes vaporariorum).        -   Geographical adaptation.—observations indicate that the            variety is suitable for warmer regions. ‘Sweeten’ performs            well in the warm temperate climate of the Northland and Bay            of Plenty regions, New Zealand. Based on this experience            indications are that ‘Sweeten’ would also perform well in            USDA plants hardiness zones 9-10 (published as the 2003 US            National Arboretum “Web Version” of the USDA Plant Hardiness            Zone Map USDA Miscellaneous Publication No. 1475, Issued            January 1990).        -   Cultivation.—protection from wind is advisable as the plant            is shallow-rooted and the branches somewhat brittle            especially under full crop load. The plant does best in            light, fertile soils, although is reputedly able to            withstand some soil compaction. Drainage is essential as the            plant does not withstand even short durations of            water-logging. Annual pruning is advisable to encourage new            shoot, and hence fruiting wood, development and to maintain            light interception within the canopy. Left unmodified,            internal shading within the canopy will result in fruiting            occurring only on the outermost branches and tips. Under            cultivation the tree can have a productive life up to about            10 years.

1. A new and distinct tamarillo plant substantially as hereinillustrated and described.